2000 gmc sierra v8 keyless entry issues.

Ok let me start of by saying I am a heavy equipment tech and pretty good with electrical issues/problems but I ran into this one and I wanted some of your more experienced guys to help me troubleshoot it. I am working on a gmc sierra, 2000, v8. The keyless entry/remote start unit is a viper one. She had a blown passenger marker light, underneath her headlight. Simple fix new bulb, but while I had that lense removed I noticed that the inner most bulb was blown and had some charring around the socket area but no burnt wiring. So I just stuck new bulbs in and proceeded to test the lights. At that time I noticed that when you hit the lock/unlock on the remote that no lights flash on the vehicle with the exception of the interior dome light. Now I asked the owner if it flashed prior to having brought it to me and they said that they used to flash front and rear with the lock/unlock on the remote. I started to think fuse somewhere so I checked all the fuses in the engine bay and in the vehicle. None are blown from what I can see. So what I need to know is what these lights are used for and if there is a relay or fuse that controls power to them so I can continue to test things and find the source of the problem.  The remote start/alarm function, lock/unlock finction all work just fine.

Me wonders why there was charring and a possible blown LIGHT FLASH fuse?

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Ideal - cmon dude, add to topics in a useful manner, not stuff that is obvious.
Story - Phzzzt! Hey, what happened?! ... Isn't it obvious?
Moral - Never dismiss the obvious.

yeah I was wondering that myself, and I will check to see if I can locate that fuse as mentioned above and check it out. I am thinking that the fuse should have burnt out long before any charring occured on the light sockets unless it was wired direct and not protected with a fuse. Unless that fuse supplies power to a relay of soem sort and the main power for those lights runs through it.

The R/S's LIGHT FLASH output is driven by an on-board relay. The fuse is on the WHITE wire, in-line between the relay and the drain. The source is on-board from the CONSTANT 12v source for the R/S. Depending on the amount and type of charring, a possible reason for it is condensation(contaminated) and vibration. The LIGHT FLASH circuit would probably have never seen it, due to it's intermittent nature. Though, anything is possible.

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Ideal - cmon dude, add to topics in a useful manner, not stuff that is obvious.
Story - Phzzzt! Hey, what happened?! ... Isn't it obvious?
Moral - Never dismiss the obvious.

dlambe wrote:

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yeah I was wondering that myself, and I will check to see if I can locate that fuse as mentioned above and check it out. I am thinking that the fuse should have burnt out long before any charring occured on the light sockets unless it was wired direct and not protected with a fuse. Unless that fuse supplies power to a relay of soem sort and the main power for those lights runs through it.

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most likely what you are going to find is the white wire from the keyless unit is connect to the BCM under the steering column and the parklights are controlled that way, if this is a new body style 2000. if its an old body style, it will most likely be at the switch. these trucks have crappy light sockets and connectors as well. the "charring" you mention is pretty common on that make/model. they also have constant problems with the connector at the fuel pump for the exact same reason.

well after checking the fuses and seeing if any were blown I found no blown fuses at the module at all. I did however notice that 1 of the fuses was loose (the white wire one) in the socket so I pushed the fuse in tight and that correceted the problem. Thanks for the help guys.